Flutter学习中遇到的问题：已有项目加入Flutter模块
2018-09-24 本文已影响199人
jzhu085
本文主要尝试解决如下几个问题：
- 如何在在已经项目加入Flutter
- 混合跳转
- 混合栈问题
- 混合栈数据问题
跳转黑屏是因为debug的缘故，打release包则没有。
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1. 如何在在已经项目加入Flutter
直接参考这篇文章Add Flutter to existing apps
2. 混合跳转
首先：Android跳转到Flutter
创建一个FlutterActivity
直接继承FlutterActivity或者自定义一个CustomFlutterActivity，我用的自定义，是做了一些封装和flutter插件注册
public abstract class CustomFlutterActivity extends AppCompatActivity implements FlutterView.Provider, PluginRegistry, FlutterActivityDelegate.ViewFactory {
private final FlutterActivityDelegate delegate = new FlutterActivityDelegate(this, this);
private final FlutterActivityEvents eventDelegate;
private final FlutterView.Provider viewProvider;
private final PluginRegistry pluginRegistry;
public CustomFlutterActivity() {
this.eventDelegate = this.delegate;
this.viewProvider = this.delegate;
this.pluginRegistry = this.delegate;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
if (injectRouter())
ARouter.getInstance().inject(this);
super.onCreate(savedInstanceState);
this.eventDelegate.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
registerCustomPlugin(this);
}
protected boolean injectRouter() {
return false;
}
//省略部分代码
.........
.........
private static void registerCustomPlugin(PluginRegistry registrar) {
FlutterPluginJumpToAct.registerWith(registrar.registrarFor(FlutterPluginJumpToAct.CHANNEL));
}
}
做一个Flutter用的容器，通过容器统一管理需要跳转的Flutter界面
@Route(path = RouterPath.MainPath.MAIN_FLUTTER_CONTAINER, name = "FlutterContainerActivity")
public class FlutterContainerActivity extends CustomFlutterActivity {
private static String CHANNEL = "com.jzhu.msg/plugin";
private static int TIME_ONE_SECOND = 1000;
@Autowired(name = "path")
String path;
@Override
protected boolean injectRouter() {
return true;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initBasicMessageChannel();
}
@Override
public FlutterView createFlutterView(Context context) {
WindowManager.LayoutParams matchParent = new WindowManager.LayoutParams(-1, -1);
FlutterNativeView nativeView = this.createFlutterNativeView();
FlutterView flutterView = new FlutterView(FlutterContainerActivity.this, (AttributeSet) null, nativeView);
flutterView.setInitialRoute(path);
flutterView.setLayoutParams(matchParent);
this.setContentView(flutterView);
return flutterView;
}
private void initBasicMessageChannel() {
switch (path) {
case RouterPath.ModuleFlutterPath.FLUTTER_HOME:
initHomeBasicMessage();
break;
case RouterPath.ModuleFlutterPath.FLUTTER_TEST:
initTestBasicMessage();
break;
}
}
private void initTestBasicMessage() {
BasicMessageChannel channel = new BasicMessageChannel<String>(
getFlutterView(), CHANNEL, StringCodec.INSTANCE);
channel.setMessageHandler((o, reply) -> {
ToastUtils.show((String)o,3000);
reply.reply("FlutterContainerActivity：回条消息给你");
});
new Handler().postDelayed(() -> channel.send("FlutterContainerActivity：发条消息给你"), TIME_ONE_SECOND);
}
private void initHomeBasicMessage() {
//todo
}
}
Flutter提供的页面
void main() {
runApp(new MaterialApp(
routes: <String, WidgetBuilder>{
'/homepage': (BuildContext context) => new MyHomePage(),
'/testpage': (BuildContext context) => new TestPage(),
}, home: new MyHomePage()));
}
路由
public interface RouterPath {
interface MainPath{
String MAIN_FLUTTER_CONTAINER = "/main/FlutterContainerActivity";
String MAIN_TEST= "/main/TestActivity";
}
interface ModuleFlutterPath{
String FLUTTER_HOME= "/homepage";
String FLUTTER_TEST= "/testpage";
}
}
点击跳转
ARouter.getInstance()
.build(RouterPath.MainPath.MAIN_FLUTTER_CONTAINER)
.withString("path", RouterPath.ModuleFlutterPath.FLUTTER_HOME)
.navigation();
最后：Flutter跳转到Android
通过插件实现，用法参考我之前写一篇Flutter知识点: Flutter与原生(Android)的交互
3. 混合栈问题
- 如果是Android的页面跳转到Android页面，所以就是普通的Activity栈。
- 如果是Android的页面跳转到Flutter页面，那么都使用了我们的容器FlutterContainerActivity，所以就是普通的Activity栈，这里面遇到个坑，下面会提出并尝试解决。
- 如果是Flutter的页面跳转到Flutter页面，那么由Flutter自己内部的栈管理。
- 如果是Flutter的页面跳转到Android页面，那么自己管自己就好啦。
如果你把Flutter的页面全装到到容器FlutterContainerActivity展示，那就都是普通的Activity栈，省事！
混合跳转注意：
- Android某些页面的启动模式Standard，SingleTop，SingleTask，SingleInstance
- Flutter页面也存在一些特殊的跳转，popAndPushNamed，pushNamedAndRemoveUntil，popUntil，pushReplacementNamed
以上需要根据实际情况处理，存在特殊跳转，销毁等逻辑
开发中需要特别需要注意的一个问题：
跳转顺序：Android页面 -> Flutter页面（使用了FlutterContainerActivity）-> Flutter页面（原始）
期望结果：Flutter页面（原始）-> Flutter页面（使用了FlutterContainerActivity）-> Android页面
真实结果：Flutter页面（原始）-> Flutter页面（使用了FlutterContainerActivity）-> Flutter页面（homepage） -> Android页面
得到疑问：我们并没有启动homepage，为什么多了一个homepage？
代码猜想：Flutter栈里初始化了一个homepage， 其他Flutter的页面都在这个栈之上。
void main() {
runApp(new MaterialApp(
routes: <String, WidgetBuilder>{
............
}, home: new MyHomePage()));
}
如何解决：使用SystemNavigator.pop()，
Tells the operating system to close the application, or the closest equivalent.
onWillPop参考这篇Flutter学习中的问题记录: 如何监听实体/虚拟返回键和AppBar返回键
class _MyHomePageState extends State<MyHomePage> {
static const jumpPlugin = const MethodChannel('com.jzhu.jump/plugin');
Future<Null> _jumpToNative() async {
Map<String, String> map = {"path": "/main/TestActivity"};
String result = await jumpPlugin.invokeMethod('jump2act', map);
print(result);
}
Future<bool> _requestPop() {
SystemNavigator.pop();
return new Future.value(false);
}
@override
Widget build(BuildContext context) {
return new WillPopScope(
child: new Scaffold(
appBar: new AppBar(
title: new Text("Home Page"),
),
body: new Center(
child: new RaisedButton(
child: new Text("跳到TestActivity"), onPressed: _jumpToNative),
),
// This trailing comma makes auto-formatting nicer for build methods.
),
onWillPop: _requestPop);
}
}
4. 混合栈数据问题，以插件的方式解决 。
MethodChannel，EventChanneld的数据传输，用法参考我之前写一篇Flutter知识点: Flutter与原生(Android)的交互
主要举例BasicMessageChannel和BinaryMessages
1_Sd6s3EDGkU8TBS9xLc4Zvw.png
FlutterContainerActivity中初始化，监听，发送
为什么要延迟发送？
因为FlutterView可能还没初始化，这时候无法接收消息
private static String CHANNEL = "com.jzhu.msg/plugin";
private static String CHANNEL_BINARY = "com.jzhu.msg.binary/plugin";
private static int TIME_ONE_SECOND = 1000;
private void initTestBasicMessage() {
BasicMessageChannel channel = new BasicMessageChannel<String>(
getFlutterView(), CHANNEL, StringCodec.INSTANCE);
channel.setMessageHandler((o, reply) -> {
ToastUtils.show((String)o,3000);
reply.reply("FlutterContainerActivity：回条消息给你");
});
new Handler().postDelayed(() -> channel.send("FlutterContainerActivity：发条消息给你"), TIME_ONE_SECOND);
ByteBuffer message = ByteBuffer.allocateDirect(256);
message.putDouble(3.14);
message.putInt(123456789);
new Handler().postDelayed(() -> getFlutterView().send(CHANNEL_BINARY,message), TIME_ONE_SECOND);
getFlutterView().setMessageHandler(CHANNEL_BINARY, (byteBuffer, binaryReply) -> {
byteBuffer.order(ByteOrder.nativeOrder());
double x = byteBuffer.getDouble();
int n = byteBuffer.getInt();
Log.i("zj", "Received: "+x+ " and "+ n);
binaryReply.reply(message);
});
}
Flutter中监听，发送
static const channel = const BasicMessageChannel<String>('com.jzhu.msg/plugin', StringCodec());
static const String channelBinary = 'com.jzhu.msg.binary/plugin';
void _sendMsg2Android() async {
_replyMsg = await channel.send('TestPage：发条消息给你');
setState(() {});
final WriteBuffer buffer = WriteBuffer()
..putFloat64(3.14)
..putInt32(123456789);
final ByteData message = buffer.done();
_replyBinaryMsg = await BinaryMessages.send(channelBinary, message);
_decodeData(message);
}
void _initMessageHandler() {
channel.setMessageHandler((String message) async {
_receivedMsg = message;
setState(() {});
});
BinaryMessages.setMessageHandler(channelBinary, (ByteData message) async {
_decodeData(message);
});
}
void _decodeData(ByteData message){
final ReadBuffer readBuffer = ReadBuffer(message);
final double x = readBuffer.getFloat64();
final int n = readBuffer.getInt32();
print('Received $x and $n');
}
